ep_create_wakeup_source(): dentry name can change under you...

or get freed, for that matter, if it's a long (separately stored)
name.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2020-09-24 19:41:58 -04:00
parent fe0a916c1e
commit 3701cb59d8
1 changed files with 4 additions and 3 deletions

View File

@ -1448,7 +1448,7 @@ static int reverse_path_check(void)
static int ep_create_wakeup_source(struct epitem *epi)
{
const char *name;
struct name_snapshot n;
struct wakeup_source *ws;
if (!epi->ep->ws) {
@ -1457,8 +1457,9 @@ static int ep_create_wakeup_source(struct epitem *epi)
return -ENOMEM;
}
name = epi->ffd.file->f_path.dentry->d_name.name;
ws = wakeup_source_register(NULL, name);
take_dentry_name_snapshot(&n, epi->ffd.file->f_path.dentry);
ws = wakeup_source_register(NULL, n.name.name);
release_dentry_name_snapshot(&n);
if (!ws)
return -ENOMEM;